Correlating Discharge Current Pulse With Surface Charge Deposition in Diverse Gaseous Environment

Abstract

The phenomenon of surface charging caused by electrical discharges has attracted significant attention because of its adverse effects on electrical systems and its industrial applications. Since the surface charging and discharge current are both influenced by the charges generated during the discharge, it is important to study the correlation quantitatively. The primary goal of the study is to analyze the relationship between the discharge current pulse and the corresponding surface charge deposition for positive and negative excitations. To establish the relation, variations were introduced in two key parameters influencing the discharge process: the discharge medium (N2, CO2, and dry air) and the pressure (100, 90, 80, 70, and 60 kPa) in each medium. The excitation voltage waveform is chosen to ensure the generation of only a single current pulse during the discharge. The positive excitation resulted in a higher pulse magnitude for N2 and dry air, whereas CO2 exhibited an opposite trend. The change in the current pulse is found to be directly proportional to the variation in charge deposition. The derived empirical formulas establish a linear correlation between the total charge computed from the current pulse and the deposited surface charge, verified by Pearson’s correlation coefficient, which suggests a good correlation strength. Of the three gaseous media, CO2 has shown a lower margin of error and consistent discharge results.